During the Seven Years' War, Tryon and his regiment were involved in the Cherbourg--St Malo operation. They landed at Cherbourg and destroyed all war making facilities. In September, they reembarked for St Malo where the operation went smoothly until the withdrawal when they came under intense fire from the French at the Battle of St Cast. Tryon was wounded in the thigh and head.

On 26 April 1764, through family connections, Tryon obtained the position of acting lieutenant governor of the Province of North Carolina. He arrived in North Carolina with his family, including a young daughter,[2] and architect John Hawks,[3] in early October to find that the previous governor, Arthur Dobbs, had not left. He said that he would not be leaving until May.[1] Tryon found himself with no income (although he was Lieutenant Governor).[2]

In 1765, a house called Russelborough on the Cape Fear River near Brunswick Town was renovated to serve as Tryon's residence while he acted as Lieutenant Governor.[2] Tryon assumed his position as acting governor when Dobbs died on 28 March 1765. On 10 July, the King promoted him to governor.

After assuming the office of governor, Tryon worked to expand the Church of England in North Carolina.[3] There were only five Anglican clergy members in North Carolina at that time.[3] Tryon pushed for the completion of abandoned construction projects of Anglican churches in Brunswick Town, Wilmington, Edenton, and New Bern.[3] Tryon appointed members of the clergy for these churches and encouraged the construction of new churches, especially in rural areas.[3]

There was strong opposition in North Carolina to the Stamp Act of 1765. When the Stamp Act Congress was held, the colonial assembly was not in session, hence delegates could not be selected to attend. Tryon refused to allow meetings of the Assembly from 18 May 1765 to 3 November 1766 to prevent the Assembly from passing a resolution in opposition to the Stamp Act.

Tryon said that he was personally opposed to the Stamp Act and that he offered to pay the taxes on all stamped paper on which he was entitled to fees. Tryon requested troops to enforce the act, but instead he was informed on 25 June 1766 that the act was repealed.

Tryon composed plans for an elaborate governor's mansion, which would also function as a central location for government business; he worked with Hawks during 1764 and 1765 to draw up plans for an elaborate home.[1][3] In December 1766, the North Carolina legislature authorized £5,000 for the building of Tryon's mansion.[3] Tryon told the legislature that the sum was not substantial enough for the plans he and Hawk had created; building it "in the plainest manner" would cost no less than £10,000 without including the outbuildings he envisioned.[3]

Hawks agreed to supervise the construction for three years and went to Philadelphia at Tryon's behest to hire workers; Tryon said native North Carolina workers would not know how to construct such a building.[3] Tryon was able to convince the legislature to increase taxes to help pay for the project.[3] The unpopularity of the new taxes spawned the derogatory nickname 'Tryon Palace'. In 1770, Tryon moved into the completed mansion.[3] The house was "a monument of opulence and elegance extraordinary in the American colonies."[3]

Although he accomplished some notable improvements in the colony, such as the creation of a postal service in 1769, Tryon is most noted for suppressing the Regulator Movement in western North Carolina during the period from 1768 to 1771. The uprising was caused partly by taxation imposed to pay for Tryon Palace at New Bern (which Tryon made the provincial capital) and partly by tax abuse and fraud by western officials.[3] Matters came to a head in May 1771, when colonial militia defeated 2,000 Regulators in the Battle of Alamance.[3]

Following the battle, Tryon ordered the execution of seven alleged Regulators, convicted by Judge Richard Henderson.[3] Most of the men were accused of violating the Riot Act, a crime temporarily made a capital offense by the General Assembly. The executed men included James Few, Benjamin Merrell, Enoch Pugh, Robert Matear, "Captain" Robert Messer, and two others.

Six other convicted Regulators – Forrester Mercer, James Stewart, James Emmerson, Herman Cox, William Brown, and James Copeland – were pardoned by King George III and released by Tryon. The Regulator uprising is viewed by some historians as a precursor to the American Revolution. Tryon then raised taxes again to pay for the militia's campaign against the Regulators.[3]

Tryon's governorship ended, and he left North Carolina on 30 June 1771. Tryon Palace was reconstructed in the 1950s using the original architectural plans drawn by John Hawks.

On 8 July 1771, Tryon arrived in the Province of New York and became its governor. In 1771 and 1772 he was successful in having the assembly appropriate funds for the quartering of British troops and also on 18 March 1772 the establishment of a militia. Funds were also appropriated for the rebuilding of New York City's defenses.

In 1772, opposition in New York was strong against the Tea Act. In December, the Sons of Liberty "persuaded" the tea agents to resign. Tryon proposed to land the tea and store it at Fort George. The Sons of Liberty were opposed and Alexander McDougall said, "prevent the landing, and kill [the] governor and all the council". When news of the Boston Tea Party arrived on 22 December, Tryon gave up trying to land the tea. He told London the tea could be brought ashore "only under the protection of the point of the bayonet, and muzzle of cannon, and even then I do not see how consumption could be effected". In 1774, the New Yorkers dumped their own consignment of tea into the harbor.

On 29 December 1773 the governor's mansion and all its contents were destroyed by fire. The New York Assembly appropriated five thousand pounds for his losses.

On 7 April 1774, Tryon departed for a trip to England. Cadwallader Colden was the acting governor of New York in Tryon's absence. He arrived back in New York on 25 June 1775 after the American Revolutionary War had begun. Isaac Sears returned in July from the Continental Congress with orders to put Tryon under arrest, but George Washington had ordered Philip Schuyler, the commander in New York, to leave Tryon alone.

On 19 October 1775, Tryon was compelled to seek refuge on the British sloop-of-war Halifax in New York Harbor. In 1776, he dissolved the assembly and called for new elections in February. The new assembly was for independence, so Tryon dissolved it.

During the spring and summer of 1776, Tryon and New York City's mayor, David Mathews, conspired in a miserably bungled plot to kidnap General George Washington and to assassinate his chief officers. One of Washington's bodyguards, Thomas Hickey, was involved in the plot. Hickey, while in prison for passing counterfeit money, bragged to his cellmate Isaac Ketcham about the kidnapping plot. Ketcham revealed it to authorities in an effort to gain his own freedom. Hickey was court-martialled, and hanged for mutiny on 28 June 1776.

In June, Admiral Howe arrived in New York City with the British army. Howe placed New York under martial law with James Robertson as the military commander. Tryon retained his nominal title as governor, but with little power.

In early 1777, Tryon was given the rank of major-general of the provincials. In April, he was ordered to invade Connecticut and march on the city of Danbury to destroy an arsenal there. Tryon established his headquarters at the house of a Loyalist named Joseph Dibble, at the south end of the village, and near the public stores. Generals Agnew and Erskine made their headquarters in a house near the bridge, at the upper end of the main street, now owned by Mr. Knapp. All the other houses in the village were filled with British troops at night.

Tryon engaged and defeated Patriot forces under the command of General David Wooster and Benedict Arnold at the Battle of Ridgefield when attempting to return to an invasion fleet anchored in Westport. In May 1778 he was given the rank of major-general in the British army, but in America only, and also the colonelcy of the 70th Regiment of Foot. He became the British commander of the British forces on Long Island.

Tryon had long advocated engaging in attacks on civilian targets, but Clinton turned down Tryon's proposals. In July 1779, Tryon commanded a series of raids on the Connecticut coast, attacking New Haven, Fairfield, and Norwalk, burning and plundering most of Fairfield and Norwalk. Tryon's raids were intended to draw American forces away from the defense of the Hudson valley. In spite of pressure from Governor Jonathan Trumbull, George Washington did not move his troops. Americans condemned him for making war on "women and children", and the British commander Clinton was also indignant about Tryon disobeying his orders. Tryon found approval of his conduct from Lord George Germain, but Clinton refused to give Tryon any further significant commands.

In September 1780, Tryon returned to his home in London, England. He directed the affairs of his 70th Regiment of Foot still in the Colonies and he gave directions in 1783 for the regiment to be brought back to England for disbandment. In 1782 he was promoted to lieutenant-general. In 1784 he was made colonel of the 29th Regiment of Foot, which was stationed in Canada.

Tryon's policies during the American Revolution were described as savagely brutal by persons on both sides of the conflict. Although he has been described as a tactful and competent administrator who improved the colonial postal service,[4] Tryon became unpopular first because he obeyed the instructions of his superiors prior to the war and then disobeyed them during the war by being overly harsh in his conduct of the war in the neutral ground in New York. For example, historian Thomas B. Allen notes on p. 202 of his book Tories that 'Tryon's desolation warfare shocked many British officers and outraged Patriots.' According to Allen, 'Joseph Galloway, a leading Tory, charged that marauding and even rape was officially tolerated by the British and the Loyalists. Galloway said that "indiscriminate and excessive plunder" was witnessed by "thousands within the British lines." In a "solemn inquiry," backed by affidavits, he said, "it appears, that no less than twenty-three [rapes] were committed in one neighborhood in New Jersey; some of them on married women, in presence of their helpless husbands, and others on daughters, while the unhappy parents, with unavailing tears and cries, could only deplore the savage brutality." Similarly, in New York City, citizens and officers accused Hessians, Redcoats, and Loyalists of robbing houses, raping women, and murdering civilians.'

Tryon Amateur Radio Club,[5] named for the Tryon County in NY, this club is located in Johnstown, NY, now Fulton County.

His name is still preserved at Fort Tryon Park in Manhattan in New York City, which was held by the British throughout most of the American Revolution.

Tryon's name remained for many years on the New York street, Tryon Row, which ran between Centre Street and Park Row in lower Manhattan. Tryon Row was the location of the New York Free School No. 1, at the corner of Chatham Street, which was one of the city's first public schools, in the early 19th century. The street's path is now occupied by the sidewalk and gardens south of the Manhattan Municipal Building.[6]

Tryon Street in South Glastonbury, Connecticut that travels along the banks of the Connecticut River. The adjacent Tryon Farms was featured in Glastonbury's yearly 2007 calendar. Sarah Jane Tryon-Betts is the land owner, as is her uncle; Charles Tryon. Many homes on Tryon Street date back to this period, and in fact accommodate the furniture of this era, some of which (such as the Cherry Highboy) were produced by the cabinetmaker Isaac Tryon, circa 1772.